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How to judge two matrixes containing the same element and delete them in one matrix?

Subject:How to judge two matrixes containing the same element and delete them in one matrix?From:dai

Hi, guys. I have coming to a problem. Since I am not familiar with the functions in the matlab, I can not solve this problem which is how to judge two matrixes containing the same element. For example, I have a = [1 2 3 4 5] and b = [4 5 6 7 8]. And now I wish to delete the same elements in a from b and get [6 7 8]. Please give me one hand.

Subject:How to judge two matrixes containing the same element and delete them in one matrix?From:us

"dai " <279711585@qq.com> wrote in message <guu4mu$ler$1@fred.mathworks.com>...
> Hi, guys. I have coming to a problem. Since I am not familiar with the functions in the matlab, I can not solve this problem which is how to judge two matrixes containing the same element. For example, I have a = [1 2 3 4 5] and b = [4 5 6 7 8]. And now I wish to delete the same elements in a from b and get [6 7 8]. Please give me one hand.

a hint:

help ismember; % and other membership functions...

us

Subject:How to judge two matrixes containing the same element and delete them in one matrix?From:Nicolaie Popescu-Bodorin

If it make sens in your application, be aware of NaN elements appearing in a or in b!

Regards,
Bodorin

"dai " <279711585@qq.com> wrote in message <guu4mu$ler$1@fred.mathworks.com>...
> Hi, guys. I have coming to a problem. Since I am not familiar with the functions in the matlab, I can not solve this problem which is how to judge two matrixes containing the same element. For example, I have a = [1 2 3 4 5] and b = [4 5 6 7 8]. And now I wish to delete the same elements in a from b and get [6 7 8]. Please give me one hand.

Subject:How to judge two matrixes containing the same element and delete them in one matrix?From:Nicolaie Popescu-Bodorin

> "dai " <279711585@qq.com> wrote in message <guu4mu$ler$1@fred.mathworks.com>...
> > Hi, guys. I have coming to a problem. Since I am not familiar with the functions in the matlab, I can not solve this problem which is how to judge two matrixes containing the same element. For example, I have a = [1 2 3 4 5] and b = [4 5 6 7 8]. And now I wish to delete the same elements in a from b and get [6 7 8]. Please give me one hand.

Subject:How to judge two matrixes containing the same element and delete them in one matrix?From:us

I think the OP's description had an error -- if we follow the procedure they
described in words, the result should be [1 2 3 6 7 8], but they said they
wanted [6 7 8]. If the expected result was incorrect and the correct answer
they expect is [1:3 6:8], we can do that in one step:

a = 1:5;
b = 4:8;
combinedData = setxor(a, b)

If not, the OP should restate what they're trying to do more clearly.

--
Steve Lord
slord@mathworks.com

Subject:How to judge two matrixes containing the same element and delete them in one matrix?From:dai

"dai " <279711585@qq.com> wrote in message <guu4mu$ler$1@fred.mathworks.com>...
> Hi, guys. I have coming to a problem. Since I am not familiar with the functions in the matlab, I can not solve this problem which is how to judge two matrixes containing the same element. For example, I have a = [1 2 3 4 5] and b = [4 5 6 7 8]. And now I wish to delete the same elements in a from b and get [6 7 8]. Please give me one hand.

All of above are very helpful for me. But I still want to know another problem. That is is a = [1 2;3 4], I wish to search the index of a given rowin the matrix. I type find(a=[3 4]), but it turned out to be wrong. So what can I do next?

Subject:How to judge two matrixes containing the same element and delete them in one matrix?From:Bruno Luong

"dai " <279711585@qq.com> wrote in message <guvqv6$kma$1@fred.mathworks.com>...
> "dai " <279711585@qq.com> wrote in message <guu4mu$ler$1@fred.mathworks.com>...
> > Hi, guys. I have coming to a problem. Since I am not familiar with the functions in the matlab, I can not solve this problem which is how to judge two matrixes containing the same element. For example, I have a = [1 2 3 4 5] and b = [4 5 6 7 8]. And now I wish to delete the same elements in a from b and get [6 7 8]. Please give me one hand.
>
> All of above are very helpful for me. But I still want to know another problem. That is is a = [1 2;3 4], I wish to search the index of a given rowin the matrix. I type find(a=[3 4]), but it turned out to be wrong. So what can I do next?

Use ISMEMBER with 'ROWS' option.

If your data are float (double or single class with fractional different zero), it is recommended not to use exact comparison. There is a ISMEMBERF in FEX

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